In a conventional coherent optical communications architecture, a transmit end transmits a complex electric field signal of polarization multiplexing. The signal is transmitted through an optical path. A receive end receives an optical signal by means of coherence reception, and performs digital signal processing on the received optical signal, to restore the complex signal of the transmit end.
Generally, a conventional optical signal receiver needs to use four analog-to-digital converters (ADCs), and therefore has relatively high power consumption.